Development of a novel rinse-off method for improved sunscreen exposure assessment.

Recent legislative measures restricting the sale of sunscreens containing certain ultraviolet light filtering ingredients (UVFs) have been based on a perception of risk to aquatic life despite the lack of a robust data set to support these decisions. Concerns were focused on the potential for recreational swimmers' and divers' sunscreen use to result in exposures to coral already stressed due to climate change, disease, and other local conditions. In published environmental risk assessments for UVFs, exposure estimates were based on episodic environmental monitoring or estimates of typical sunscreen use, arbitrarily assuming the portion rinsed off from skin in seawater. To improve the accuracy of exposure estimates and thereby develop more robust risk assessments, we measured the amount of the UVFs, avobenzone, homosalate, octisalate, octocrylene, and oxybenzone released to seawater from four sunscreen products (two lotions, one spray, one stick) in a novel porcine skin model of typical human sunscreen use. Sunscreen was applied to porcine skin, allowed to briefly dry, then exposed to four rinse cycles in artificial seawater. The mass of each UVF in seawater, partitioned from seawater onto glassware, and extractable from skin after rinsing were determined. The proportion rinsed from skin varied by UVF, by formula type, and by application rate. Less than 1.4% of applied octisalate, homosalate, and octocrylene was detected in seawater samples (independent of formula) increasing to an average of 4% and 8% for avobenzone in stick and lotion forms, and to 24% for oxybenzone in lotions. The initial data show substantial differences in rinse-off among formulation types and sunscreen application rates, and stress the importance of using UVF-specific rinse-off values rather than a single value for all UVFs. This new method provides a tool for more robust exposure estimates, with initial data supporting lower rinse-off values than adopted in published risk assessments. Integr Environ Assess Manag 2021;17:961-966. © 2021 Johnson & Johnson Consumer Companies Inc. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Biochemical and aerosol characterization of ricin for use in non-clinical efficacy studies.

Ricin toxin may be used as a biological warfare agent and no medical countermeasures are currently available. Here, a well-characterized lot of ricin was aerosolized to determine the delivered dose for future pre-clinical efficacy studies.  Mouse intraperitoneal (IP) median lethal dose (LD50 ) bioassay measured potency at 5.62 and 7.35 µg/kg on Days 0 and 365, respectively. Additional analyses included total protein, sodium dodecyl sulfate polyacrylamide gel electrophoresis, Western blotting, and rabbit reticulocyte lysate activity assay. The nebulizer aerosol produced consistent concentrations (2.5 × 103 , 5.0 × 103 , 1.0 × 104 , and 1.5 × 104  µg/mL) and spray factor values. The aerosol particle size distribution was of sufficient size to deposit in lung alveoli (1.12-1.43 µm). Ricinus communis Agglutinin II (RCA 60), prepared at 19 mg/mL in phosphate-buffered saline, pH 7.8, and stored at -70°C, maintained attributes for toxicity following 1-year storage and aerosolized consistently.